1. Field of the Invention
The present invention relates to a spectrum detector, and more particularly, to a spectrum detector including a plurality of photodetectors, each of which has a concavo-convex pattern formed on a semiconductor device.
2. Discussion of the Background
In general, a diffraction grating is frequently used to implement a spectroscopic analysis of light with respect to wavelengths for the purpose of measuring the spectra of light exiting a light source. The diffraction grating is formed to have 1200 to 1600 gratings (slits) per millimeter. If the diffraction grating is rotated about an axis of the diffraction grating, light of a specific wavelength is incident on one slit. Both ends of the grating are machined so that their angles are not constant.
Recently, a small-sized wavelength spectrometer using such a diffraction grating and a charge-coupled device (CCD) has been produced. This wavelength spectrometer requires a considerable distance between the diffraction grating and the CCD. A visible wavelength spectrometer generally has a size of 5 cm×10 cm×3 cm or so.